This invention relates to an apparatus for raising a sow in a farrowing crate relative to a floor for the piglets for reducing piglet mortality by crushing as the sow lies or treads during movement to access feed and water.
In British patent 932189 (Hodgkinson) issued in 1963 is shown a farrowing crate or pen for sows where the level of the outer floor section which carries the piglets can be raised and lowered in order to move the piglets away from danger from the sow when the sow is standing. Thus when the sow lies down, the piglets are kept away from the height of the floor level on which the sow lies to reduce the possibility of crushing.
This arrangement uses a light beam and electric switches to detect the movement of the sow and uses a complex lifting arrangement. The device is currently not available on the market.
U.S. Pat. No. 4,793,287 of Hoffmann issued in 1988 discloses a modified arrangement in which lifting and lowering of the piglet floor section is actuated by an alternative arrangement. However again this construction is disadvantageous and is not available in the market place.
It is one object of the present invention, therefore, to provide an improved apparatus for raising and lowering a sow in a farrowing pen.
According to one aspect of the invention there is provided a farrowing pen or crate for sows comprising:
a floor assembly for receiving the sow and piglets which includes a first floor section on which the sow can stand and lie and two second floor sections each on a respective side of the first floor section for receiving piglets of the sow;
the floor assembly including a support structure for supporting the floor sections;
confining walls for locating the sow on the first floor section;
the support structure including a separate support element for carrying the first floor section;
a base member under the floor assembly on which the support element is mounted;
a lift mechanism, operated by a power source, carried on the base member and arranged to raise and lower the support element with the first floor section thereon relative to the second floor sections between a lowered position in which the first floor section is level with the second floor sections and a raised position in which the first floor section is raised to a height which prevents the sow when lying crushing the piglets on the second floor sections;
and a sensor responsive to movement of the sow tending to stand to actuate the lift mechanism to raise the first floor section and responsive to movement of the sow to a lying position to actuate the lift mechanism to lower the first floor section.
Preferably the sensor comprises a switch which is arranged at the floor for pressure on the switch when the sow is lying.
Preferably the switch includes an actuator which is covered by a cover plate on to which the sow can lie.
Preferably the cover plate is a channel resting along floor bars of the first floor section.
Preferably the lift mechanism includes an air bag and the power source comprises a supply of compressed air and wherein the sensor is arranged for actuating an air supply valve. However other lift mechanisms can be used including a hydraulically actuated cylinder which drives the lifting action through a suitable linkage such as a scissors type linkage, and including an electric screw type system, depending upon the power source available and selected for use. However the air actuated system using an air bag is preferred in that it is resistant to corrosion and uses readily available air from a compressor.
Preferably the lift mechanism includes a guide structure for guiding movement of the first floor section in a vertical direction while maintaining the first floor section horizontal. This can be a set extendible vertical guide legs at horizontally spaced positions relative to the first floor section or other guide arrangements can be used which provide a lower profile such as parallel links connected by a rod.
In most cases, the floor sections are arranged above a manure pit having a bottom wall for receiving manure falling through the floor and the base member is carried at a position above the bottom wall of the pit as to support the lift mechanism above the manure.
The base member is preferably carried on a support mounted above the bottom of the pit to support the lift mechanism above the manure and to keep it raised above the pit floor to allow the use of conventional scrapers along the pit floor. In this arrangement, preferably the base member is carried on a cradle supported from the top of the pit to support the lift mechanism above the manure.
Preferably the lift mechanism is arranged such that the time for lowering of the first floor section from the raised position to the lowered position is longer than the time for raising.
Preferably there is provided a manually operable switch for controlling the lift mechanism by which the first floor section can be lowered for release of the sow and by which the first floor section can be raised to maintain the piglets in the second floor section for catching.
According to a second aspect of the invention there is provided a farrowing pen for sows comprising:
a floor assembly for receiving the sow and piglets which includes a first floor section on which the sow can stand and lie and two second floor sections each on a respective side of the first floor section for receiving piglets of the sow;
the floor assembly including a support structure for supporting the floor sections;
confining walls for locating the sow on the first floor section;
the support structure including separate support elements for carrying the first and second floor sections;
a base member under the floor assembly on which the support element is mounted;
a lift mechanism, operated by a power source, carried on the base member and arranged to raise and lower one of the support elements relative to the other between a position in which the first floor section is level with the second floor sections and a position in which the first floor section is at a height above the second floor section which prevents the sow when lying crushing the piglets on the second floor sections;
and a sensor responsive to movement of the sow tending to stand to actuate the lift mechanism to operate the lift mechanism;
wherein the floor sections are arranged above a manure pit having a bottom wall for receiving manure falling through the floor and wherein the base member is carried at a position above the bottom wall of the pit as to support the lift mechanism above the manure;
and wherein the base member is carried on a support mounted above the bottom of the pit to support the lift mechanism above the manure.
According to a third aspect of the invention there is provided a farrowing pen for sows comprising:
a floor assembly for receiving the sow and piglets which includes a first floor section on which the sow can stand and lie and two second floor sections each on a respective side of the first floor section for receiving piglets of the sow;
the floor assembly including a support structure for supporting the floor sections;
confining walls for locating the sow on the first floor section;
the support structure including separate support elements for carrying the first and second floor sections;
a base member under the floor assembly on which the support element is mounted;
a lift mechanism, operated by a power source, carried on the base member and arranged to raise and lower one of the support elements relative to the other between a position in which the first floor section is level with the second floor sections and a position in which the first floor section is at a height above the second floor section which prevents the sow when lying crushing the piglets on the second floor sections;
and a sensor responsive to movement of the sow tending to stand to actuate the lift mechanism to operate the lift mechanism;
wherein the sensor comprises a switch which is arranged at the floor for pressure on the switch when the sow is lying.
According to a fourth aspect of the invention there is provided a farrowing pen for sows comprising:
a floor assembly for receiving the sow and piglets which includes a first floor section on which the sow can stand and lie and two second floor sections each on a respective side of the first floor section for receiving piglets of the sow;
the floor assembly including a support structure for supporting the floor sections;
confining walls for locating the sow on the first floor section;
the support structure including separate support elements for carrying the first and second floor sections;
a base member under the floor assembly on which the support element is mounted;
a lift mechanism, operated by a power source, carried on the base member and arranged to raise and lower one of the support elements relative to the other between a position in which the first floor section is level with the second floor sections and a position in which the first floor section is at a height above the second floor section which prevents the sow when lying crushing the piglets on the second floor sections;
and a sensor responsive to movement of the sow tending to stand to actuate the lift mechanism to operate the lift mechanism;
wherein the lift mechanism includes an air bag and the power source comprises a supply of compressed air and wherein the sensor is arranged for actuating an air supply valve.